In some corners of Jamaica Saturday night, it is possible that there was just the slightest twinge of regret. After all, their women did not manage to sweep the medals in the 100-meter dash, as they did in Beijing. Gold and bronze would just have to do.

Round 2 comes Sunday night in the men's 100 meters when, again, the Jamaican people will hope for a medal sweep that, while perhaps not probable, is certainly possible.

This is the world that the Jamaican sprinters – and their American opponents – now find themselves living in, and for the Americans, it is taking some getting used to.

Since the beginning of the modern Olympics, Americans sprinters – and particularly the American men – have owned the 100 and 200 meters, the signature events of the Olympic track and field program. Only twice since the 100-meter event began in 1908 has an American man not been on the podium in a nonboycotted Games. In the 200 meters, American men have swept the medals six times.

With the Jamaicans turning the tables on the US in Beijing, winning all four races and collecting seven medals in the process, questions dogged the Americans. What was wrong? The answer, it seems, was that the Jamaicans are what's wrong with US sprinting, and short of hoping that the team plane lands in London, Ont., instead of London, England, it's not something that the US can do a lot about.

"What we are seeing is a rise in the level of the Jamaican sprinters," says David Wallechinsky, author of "The Complete History of the Olympics." "You can't prevent the rest of the world from getting better."

"It's not that the Americans are getting worse," he adds. "The world is catching up."

American Carmelita Jeter certainly feels as though there is nothing she could have done better in the 100 meters Saturday night. After failing to make the 2008 Olympic team, she rededicated herself to the sport with the sole purpose of becoming the fastest woman in the world. By many measures, it has worked: She is the 2011 world champion and the current world-record holder in the 100.

On Saturday, after all that preparation, "I executed the race the best I could have," said Ms. Jeter.

Still, Jamaica's Shelly-Ann Fraser-Pryce ran it faster, winning gold for the second Olympics in a row. "She ran an amazing race," Jeter added.

The recognition that America is no longer the alpha male (or female) of the sprinting world is pervasive, though perhaps not always explicitly acknowledged. At a media summit in May, American 200-meter sprinter Wallace Spearmon said of his teammates: "None of us runs for second place, and I think that's the best thing going for us. None of us is going to hand this to" the Jamaicans.

But the very suggestion that the US could be content with second place is, if not unprecedented, then at least unfamiliar, and it speaks to the Jamaicans' relentless pursuit of the podium in recent years.

Top Jamaicans used to emigrate

In truth, Jamaicans have long been among the medals in the Summer Olympic sprints, the world just didn't know they were Jamaicans. Poverty and a lack of training opportunities have meant that Jamaica has been little more than a sprinting nursery, sending many of its most promising prodigies abroad to be honed – and to compete for their adopted countries.

The world was perfectly happy with this arrangement. Even some inside Jamaica were. "They thought the system worked well, sending [our athletes] to finishing school in the US," says Bruce James, a top track coach in Jamaica.

But he had other ideas. Jamaican athletes and coaches, he says, needed "to believe in themselves."

So he helped start the MVP Track & Field Club in 1999, which together with Racers Track Club, have become Jamaica's two premier "finishing schools" for track athletes. Racers trains 100 meter men's favorites Usain Bolt and Yohan Blake, MVP trains Saturday's winner Ms. Fraser-Pryce as well as Asafa Powell, the third member of the potential medal sweep in the men's 100 Sunday.

In a decade, the clubs have reshaped Jamaican expectations at the Summer Olympics. Beijing brought a record 11 medals – all in sprints. James is predicting more in London, noting the rise of Blake in the men's sprints, the continued strength of the women, and national improvement in the 400 meters.

"There are significant areas we could improve our performance from the Beijing Games," he says.

A national aspiration

For the US, in particular, that is a frightening thought. But for the past few decades, at least, Jamaica's success has really only been a question of whether it could get its act together. The passion that the country has for sprinting is irrepressible.

"Everybody grows up wanting to be a track star," said Sanya Richards-Ross, an American 400-meter sprinter who was born in Jamaica but left for the US at age 12, at the media summit.

Now, with results at last matching talent, the enthusiasm at home has been a bit overwhelming for some.

"Thinking about what Jamaicans want is a bit pressuring," said Fraser-Pryce after her race. "So I try not to think about what Jamaicans want until I get the job done."